/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// Licensed to the Software Freedom Conservancy (SFC) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The SFC licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package org.openqa.selenium;

import java.util.Arrays;

/**
 * Representations of pressable keys that aren't text.  These are stored in the Unicode PUA (Private
 * Use Area) code points, 0xE000-0xF8FF.
 *
 * @see <a href="http://www.google.com.au/search?&amp;q=unicode+pua&amp;btnK=Search">http://www.google.com.au/search?&amp;q=unicode+pua&amp;btnK=Search</a>
 */
public enum Keys implements CharSequence {

  NULL         ('\uE000'),
  CANCEL       ('\uE001'), // ^break
  HELP         ('\uE002'),
  BACK_SPACE   ('\uE003'),
  TAB          ('\uE004'),
  CLEAR        ('\uE005'),
  RETURN       ('\uE006'),
  ENTER        ('\uE007'),
  SHIFT        ('\uE008'),
  LEFT_SHIFT   (Keys.SHIFT),
  CONTROL      ('\uE009'),
  LEFT_CONTROL (Keys.CONTROL),
  ALT          ('\uE00A'),
  LEFT_ALT     (Keys.ALT),
  PAUSE        ('\uE00B'),
  ESCAPE       ('\uE00C'),
  SPACE        ('\uE00D'),
  PAGE_UP      ('\uE00E'),
  PAGE_DOWN    ('\uE00F'),
  END          ('\uE010'),
  HOME         ('\uE011'),
  LEFT         ('\uE012'),
  ARROW_LEFT   (Keys.LEFT),
  UP           ('\uE013'),
  ARROW_UP     (Keys.UP),
  RIGHT        ('\uE014'),
  ARROW_RIGHT  (Keys.RIGHT),
  DOWN         ('\uE015'),
  ARROW_DOWN   (Keys.DOWN),
  INSERT       ('\uE016'),
  DELETE       ('\uE017'),
  SEMICOLON    ('\uE018'),
  EQUALS       ('\uE019'),

  // Number pad keys
  NUMPAD0      ('\uE01A'),
  NUMPAD1      ('\uE01B'),
  NUMPAD2      ('\uE01C'),
  NUMPAD3      ('\uE01D'),
  NUMPAD4      ('\uE01E'),
  NUMPAD5      ('\uE01F'),
  NUMPAD6      ('\uE020'),
  NUMPAD7      ('\uE021'),
  NUMPAD8      ('\uE022'),
  NUMPAD9      ('\uE023'),
  MULTIPLY     ('\uE024'),
  ADD          ('\uE025'),
  SEPARATOR    ('\uE026'),
  SUBTRACT     ('\uE027'),
  DECIMAL      ('\uE028'),
  DIVIDE       ('\uE029'),

  // Function keys
  F1           ('\uE031'),
  F2           ('\uE032'),
  F3           ('\uE033'),
  F4           ('\uE034'),
  F5           ('\uE035'),
  F6           ('\uE036'),
  F7           ('\uE037'),
  F8           ('\uE038'),
  F9           ('\uE039'),
  F10          ('\uE03A'),
  F11          ('\uE03B'),
  F12          ('\uE03C'),

  META         ('\uE03D'),
  COMMAND      (Keys.META),

  ZENKAKU_HANKAKU ('\uE040');

  private final char keyCode;
  private final int codePoint;

  Keys(Keys key) {
    this(key.charAt(0));
  }

  Keys(char keyCode) {
    this.keyCode = keyCode;
    this.codePoint = String.valueOf(keyCode).codePoints().findFirst().getAsInt();
  }

  public int getCodePoint() {
    return codePoint;
  }

  public char charAt(int index) {
    if (index == 0) {
      return keyCode;
    }

    return 0;
  }

  public int length() {
    return 1;
  }

  public CharSequence subSequence(int start, int end) {
    if (start == 0 && end == 1) {
      return String.valueOf(keyCode);
    }

    throw new IndexOutOfBoundsException();
  }

  @Override
  public String toString() {
    return String.valueOf(keyCode);
  }

  /**
   * Simulate pressing many keys at once in a "chord".  Takes a sequence of Keys.XXXX or strings;
   * appends each of the values to a string, and adds the chord termination key (Keys.NULL) and
   * returns the resultant string.
   *
   * Note: When the low-level webdriver key handlers see Keys.NULL, active modifier keys
   * (CTRL/ALT/SHIFT/etc) release via a keyup event.
   *
   * Issue: http://code.google.com/p/webdriver/issues/detail?id=79
   *
   * @param value characters to send
   * @return String representation of the char sequence
   */
  public static String chord(CharSequence... value) {
    return chord(Arrays.asList(value));
  }

  /**
   * @see #chord(CharSequence...)
   * @param value characters to send
   * @return String representation of the char sequence
   */
  public static String chord(Iterable<CharSequence> value) {
    StringBuilder builder = new StringBuilder();

    for (CharSequence seq : value) {
      builder.append(seq);
    }

    builder.append(Keys.NULL);
    return builder.toString();
  }

  /**
   * Get the special key representation, {@link Keys}, of the supplied character if there is one. If
   * there is no special key tied to this character, null will be returned.
   *
   * @param key unicode character code
   * @return special key linked to the character code, or null if character is not a special key
   */
  public static Keys getKeyFromUnicode(char key) {
    for (Keys unicodeKey : values()) {
      if (unicodeKey.charAt(0) == key) {
        return unicodeKey;
      }
    }

    return null;
  }
}
